Aeroplane-propeller



GEORGE FL WEmER, or DAYTON, omo.

AER/OPLANE-IPRQPELLER.

Specification of Letters Patent.

Patented Sept. 6, i921.

Application filed December 26, 1919. Serial No. 347,331..

To aZZ whom t may concern.:

Be it known that I, GEORGE F. WErHER, a citizen of the United States,residing at Dayton, in the county of Montgomery and' have inventedcertain new' State of "hio, and useful Improvements inAeroplane-Propellers, of which the following is a specification.

The principal object of the invention is to provide an aeroplanepropeller, the pitch or lead of whose blades is automatically controlledor regulated in accordance with the speed of the engine. When the speedof the engine increases, my improved regulating means under theinfluence of centrifugal force, will automatically increase the pitch orangle or incidence of the blades, to give them a greater lead perrevolution of the propeller, thereby driving the aeroplane faster thanit would be driven under the same conditions by a lixed pitch propeller.

When the motor is being started, the pitch of the blades will beautomatically reduced to a point where the pull on the engine will notbe great enough to stall it, nor prevent it from developing powerquickly after 1t is started.

In the above respects my invention performs a function similar to thatof the transmission mechanism of an automobile, by

' providing the reduced resistance of low speed gears. at the start, andincreasing the gear ratio thereafter,

The preferred forni; of embodiment of my invention is illustrate *in theaccompanyln drawings, of which Figure l is alongltudi nal section takenhorizontally through my improved variable pitch propeller. F1 2 1s a lon'tudinal throng the same. Fig. 3 is a/cross sectional view taken on theline w-a of Fig. 1. And

. Fig. 4 is a cross sectionalview taken on the line b-b of Fig. 1.

Throughout the specification and draw.-

ings, simllar reference charactersdenote corresponding parts.

Referring to the accompanying drawings,

the numerals 1 and.2 each designa-te a longitudinally shelved castingpre erably made of a1uminum,to receive the laminated pro peller blades.The castinggl firmly receives the laminated wood sections 3 of apropeller blade 4, while in the casting 2 are iirmly Secured the innerends of the laminated wood sections `5 of a propeller blade 6. (See Fig.1.)

sectiontaken, vertlcally portion which enters a `housing to project itsthreaded Each .aluminum casting has axially disposed withln it, anintegral tubular central portion 7 internally .to receive the externallythreadedouter end of a slidable tube now to be described.

Adapted to be connected to the engine shaft (not shown) is a housing 9.lnto the latter there projects through a bushing 8, the innerV end of atube 10 whose outer end is threaded intothe tubular central portion 7 ofthe aluminum' casting 1. Within thev housing 8 the tube 10 telescopesinto a tube 11 which passes through a bushing 12 in said outer end intothe tubular central portion 7 of the aluminum casting 2. `(See Figs. land 2.) The tubes 10 and 1l are moved into and out of the housing 8 bythe following means, to vary the pitch vof vthe blades which they carry,to conform to the speed of the motor.

Referring to Fig. 4.-, there are provided within the housing 8, at itsfront portion, a pair of oppositely disposed lugs 13, 13 to. which isbolted a transverse member 14. To the middle portion of the latter issecured one end of a pin 15. The latter terminates at its opposite endin an enlarged threaded lug 16 on the inner side of thehousing 8. Thispin projects through a pair of oppositely angled slots 17 provided inthe tube 11, and a pair of oppositely angled slots 18 provided in thetube 10, whereby, when said tubes are drawn outwardly by ycentrifugalforce, the pin 15 will 'turn them toincrease the pitch of the bladeswh1ch they carry.` This is due to the engagement of the pin 15 with thewalls of the inclined slots 17 and 18 "in the tubes 11 and 10respectively, when the latter are forced outwardly by centrifugal forceas the speed of the engine increases.

For the pu se of forcing the tubes 10 and l1 inwar y blades connected tothem, when the speed of the engine. is reduced, the followingconstruction 1s provided.- Surrounding the tube 10 at one end of thehousing 8, ifs, a coil spring 19, while a similar spring 20`encircles te tube 11 at the other end of the housing. Bearing against the inner endof each spring is an annular member 21 between-'which and a collar 22-there are disposed ball bearin s 23 to lreduce friction when the collar22 1s turned by the/following means. r

4@n each of the tubes 10 and 11 therel is to reduce the pitch of the ithreaded a sleeve 24 adapted to engage a rei spective collar 22 tocompress the spring between it and the end of the housing when itsrespective tube is moved outwardly by centrifugal force. Duringthisqoutward movement of the tubes, the stationary springs 19 and 20will interpose but little resistance to the turning movement which saidtubes are given by the slot and pin construction described, for the ballbearings 23 provide an anti-friction contact between the stationaryannular member 21 which engages a spring, and the rotatable collar 22which is turned by a respective sleeve. When the speed of the motordecreases, the compressed springs 19 and 20 will force the tubes 10 and11 vinwardly, and during their inward movement the slot and pinconstruction described will turn them in a reverse direction to reducethe pitch of the blades which they carry. lt will thus be seen that whenthe speed of the motor increases, centrifugal force will move the tubesoutwardy to increase the pitch of the blades; and that when the speed otthe engine decreases, the force of the compressed springs will returnthe tubes to their normal inward positions to decrease the pitch oi theblades connected to them.

For the purpose oi preventing one blade from obtaining a greater leadover the other, due to a slight variance that might occur in the tensionof one of the springs 19 or 20; or in other words, to keep the pitch ofthe blades uniform at all times, the following means are provided.Formed in the extreme inner end of the tube 10 is a pair ofoppositelypinclined slots 25 through which there loosely projects a pin26 diametrically secured within the tube 11. Accordingly, when the tubesare turned by the pin 15 that projects through the slots 17 and 1 8, thepin 26 that projects through the slots 25 will not permit one tube toobtain a greater lead than the other. In other words, the blades carriedby the tubes 10 and 11 will be maintained at auniform pitch at alltimes.

Having described my invention, l claim:

1. A propeller for aeroplanes comprising a central housing, twotelescoping tubes proj ecting outwardly .in opposite directions, fromsaid'housing, a blade carried byeach tube, each tube being provided witha pair oi oppositely inclined slots, and apin secured within thehousing, that projects loosely through each pair of slots, for thepurpose of turningr said tubes to vary the pitch of the blades whichthey carry, when moved outwardly by centrifugal force.

2. An aeroplane propeller comprising a central housing, two telescopingtubes projecting outwardly, in opposite directions, from said housing, ablade carried by each tube, each tube being provided with a pair'jecting outwardly,

bearings i Y spective annular member, to provide an antiof oppositelyinclined slotsya pin secured within said housing, that projects looselythrough each pair of slots, an annular member on each tube within thehousing, and a springinterposed between each annular member and itsrespective end of the housing, to return said tubes to their normalinward positions after they have been centrifugally moved.

3. An aeroplane propeller comprising a central housing, two telescopingtubes projecting outwardly, in opposite directions, from said housing,means for turning said tubes when the latter are moved outwardly bycentrifugal `force, a shelved casting threaded on the outer end of eachtube, and a laminated propeller blade firmly secured to said shelvedcasting.

4. An aeroplane propeller comprising a central housing, two telescopingtubes projecting outwardly, in opposite directions, from said housing, ablade carried by each tube, means for automatically turning said tubeswhen the latter are moved outwardly by centrifugal force to increase thepitch of said blades, and means for holding the pitch relationoi saidtubes to eachother, uniform at all times.

5. An' aeroplane propeller comprising` a central housing, twotelescoping tubes projecting outwardly, in opposite directions, Jfromsaid housing, ablade carried by each tube, means for automaticallyturning said tubes when the latter are moved outwardly by centrifugalforce, and a pin secured within one tube projecting through a pair ofoppositely inclined slots in the other, automatically to prevent theblade carried by one tube from securing a lead over the blade carried bythe other tube.

6. An aeroplane propeller comprising a central housing, two telescopingtubes proin opposite directions, from said housing, a blade carried byeach tube, means for automatically turning said tubes when the latteraremoved outwardly by centrifugal force to increase the. pitch ot saidblades, a coil spring surrounding each tube within the housing, anannular member encircling each tube, in engagement with its respectivespring, a collar surrounding each tube, a sleeve threaded on each tube,in engagement with said collar, and ball between each collar and itsrefriction contact between them when the tubes are turned to vary thepitch of the vblades which they carry.

ln testimonywhereoi` I have hereunto set my hand this 20th day ofDecember, 1919.

GEORGE r. wEIHEn.

"Witness:A

,l HOWARD S, SMITH.

